Folding square



PATaNr orales.

JOHN MCFADDEN, OF SOUTH.' CHECAGO, ILLINOIS.

FOLDING SQUARE.

Specification of Letters Patent.

Fatented Dec. 20, 1921.

Application filed May 25, 1920. Serial No.` 384,066.

To all whom it may concern:

lie it known that l, JOHN MCFADDEN, a citizen of the United States,residing at South Chicago, in the county of Cool; and State of illinois,have invented new and usei'ul lmprovements in Folding Squares, of whichthe following is a speciication.

This invention relates to a folding square and has t'or its primaryobj-ect the construction of a square that may fold into a very compactformation and may be readily forced to its extended position and rigidlyheld at such position.

in object or' the invention is the construction of a joint whereby themembers may he folded into parallel relation or may extend at rightangles to each other and rigidly lock :in this position. j

l/Vith these and other objects in view the invention will be betterunderstood from the following detailed description taken in connectionwith the accompanying drawing wherein: i

Figure l is a side elevation of my invention when in extended position.

Fig. '2 is a view showing the square in folded position.

Fig. 3 is an edge elevation.

Fig. 4c is an enlarged sectional view.

gain referring to the drawing illustratin?,1 one construction of myinvention the numeral l designates a main member, and the numeral 2designates an auxiliary member. The main member l is formed with a slot3 receiving the extension l that extends at right angles to theauxiliary member E2. A rivet 5 pivotally connects the extension tomember l in such a manner that the member 2 may told into parallelrelation with member l, as illustrated in ig. 2 of the drawing, or itmay be extended at right angles to the member 2. as illustrated in Fig.l or" the drawing.

rllhis joint also assures accurate ar rangement of the division marks 6of the member 2 with the division marks 7 of the member l. F or thepurpose of accurately and rigidly connecting the members together Alhave illustrated the locking device 8 consisting of a tapering iierrule9 engaging the tapering' holes i0 in the members and drawn into tightengagement therewith by the screw l1.' l? rom the foregoing' descriptiontaken in connection with the accompanying drawingit will be apparentthat I provide a square that may be readily folded and may be just asreadily extended and accurately locked in extended position so as toaccomplish accurate measurements and to assure member 2 extending` atright angles to member l.

t is, ot course, to be understood that the invention may be constructedin various other manners and the parts associated in diderent relationsand, therefore, l do not desire to be limited in any manner except asset forth in the claim hereunto appended.

Having thus described my invention what l claim is:

A folding square comprising a main memw ber having' a slot formed in oneend portion, an auxiliary member having an extension at right anglesthereto and arranged in said slot, said main member and extensionprovided with tapering holes adapted to be placed in alinement when themembers are disposed at right angles to each other, a pivot pinconnecting the main member and extension, a'frusto-conical ferrule insaid tapering holes and provided with a threaded bore, a cap screwthreaded in said threaded bore to draw the errule in tight engagementwith the holes, said main member recessed to receive the head of saiderrule.

ln testimony whereof l allix my signature.

JOHN MCFADDEN.

